The Warden's Keep was created by members of the DAO team while the rest of the team worked on finishing the PC and console versions. It was never in the core game and has been added in once the core game is complete. This extra team is working on more DLC for the coming months. We have lots of plans in the works for coolness to come.
Shale (the Stone Prisoner) WAS originally going to be in the core game. However, Shale was cut as the team could not get things such as pathfinding, etc working correctly in time to meet our projected release date. Back when DAO was going to be released back in the spring of 2009, the decision was made to cut him. Since the team had extra time once the release date was moved to November, the Dev team worked to fix the outstanding issues and included this back into the game as Day 1 DLC.
Blood Dragon Armor. This was added in a few months ago as a cool way to tie both Dragon Age and Mass Effect together.
There. Refuted yet?